These are the other three from my collection. 2 early ones with black painted aluminium cup ( 37 and 39 dated), and a mid/late war one with green painted steel cup, which is also painted red inside against rust I think. This one is dated 43' and has a nice LUX-canvas/tropical strap, which is reinforced with leather.

Merdock, your canteen is a army issued one, so yes, there should be a cup.
If I'm correct there are some para-military branches that had smaller bottles with no cup, but I'm not sure exactly which branches that were.

IMO, the mountain bottle never had a strap like the medical model does.

You're right, sorry, I was a little bit confused.

will search for more pictures concerning those large bottles used in Africa.

here's another one that shows a soldiers wearing two 'normal seize' canteens on his way to the Greec island ' Dodekanesos'. This photograph was taken in september 1943 ( WW2, day by day ;Anthony Shaw).